A new motorway west of Stockholm linking the north and south side of Stockholm is under development – the so-called "Stockholm By-Pass" ("Förbifart Stockholm"). The new link is a 21 km long highway, of which 18 km is in tunnels. At the interchange of Lovön, four intake and exhaust air stations are planned, being in close proximity to the main tunnels and ramps. In this area, there is also a deformation zone going through the intake and exhaust air station.

Itasca's Role

Itasca conducted three-dimensional numerical analysis using 3DEC of the air station. Both linear-elastic and elastic-plastic material models were used.

Project Results

The large-scale stability, the large roof areas of the intersections, pillars in the ramp connections, and the influence of the deformation zone was investigated. Conclusions from the model and recommendations for the excavation were provided.